1. Field of the Invention
The present invention relates to devices and techniques for monitoring a computer system. More specifically, the present invention relates to techniques for regulating the power-supply efficiency of computer systems based on measured power-supply output loads.
2. Related Art
As the cost of electricity to power and cool servers in data centers begins to approach the acquisition cost of the servers, it is becoming increasingly important to operate these servers in a power-efficient manner. In order to maximize the power efficiency of servers, it is important to maximize the power efficiency of the server components, such as power supplies.
Typically, power supplies are configured to operate over a fairly wide range of output loads. However, the operating power-conversion efficiency of a given power supply is a nonlinear function of its output load. For example, while a power supply may have maximum power-conversion efficiency at 85% output load, the power-conversion efficiency for output loads above and below this point can drop by 10% or more. Therefore, even though a power supply may have a high power-conversion efficiency, when it is used in a server it may operate in an output-load regime where the power-conversion efficiency is sub-optimal. Consequently, specifying a power supply with high power-conversion efficiency may not guarantee that a server operates in a power-efficient manner, unless the power supply has a constant power-conversion efficiency over the entire range of output loads. Unfortunately, this is not the case for most power supplies.
Hence, there is a need for techniques to ensure that servers, and more generally computer systems, operate in a power-efficient manner without the above-described problems.